Research And Optimal Design Of Mechanics And Fatigue Characteristics Of Automobile Control Arm

With the advent of the era of automobile electrification,the development of lightweight and high-strength auto parts has always been the research goal of engineers.As an efficient analysis method,finite element analysis has been widely used in the field of auto parts development.As a mature optimization design method,shape optimization has been used to guide the development and design of auto parts.The control arm is the key structure in the automobile suspension system,and the improvement of its performance,reliability,especially fatigue performance has always been the research direction of automobile engineers.Based on the actual product optimization and improvement project of the enterprise,this paper takes a certain automobile control arm as the research object,and carries out the following research work:The stiffness and strength tests of the control arm were carried out.The stiffness in X and Y directions and the tensile / yield strength in Y direction were tested.The three-dimensional numerical model of the control arm is established,the mesh is divided and the finite element model is established.The stiffness,strength,stress under typical limit conditions and the first six constraint modes are calculated by using the finite element analysis software,and the performance evaluation is carried out.The test results of the bench test are compared with the results of the finite element calculation,which verifies the correctness of the finite element analysis method in the performance calculation and analysis of the control arm.The fatigue characteristics of the control arm are studied,and the fatigue performance of the control arm is calculated based on the strain analysis method.The load spectrum of the control arm is analyzed by rain flow counting and pseudo damage.Based on the peak valley extraction method,the small load in the load spectrum is identified and deleted.The acceleration fatigue load spectrum of the control arm is obtained,and the time length of the load spectrum is reduced by 26%.Then the acceleration load spectrum is used to analyze and verify the fatigue of the control arm,and the bench test is carried out to verify the consistency with the analysis,and the fracture results of the road test are reproduced.The time of fatigue test is shortened by accelerating the compilation of load spectrum.The multi-objective shape optimization of the control arm is studied.The multi-objective shape optimization method based on linear weighting is adopted.The weight of multiple optimization sub objectives is determined based on AHP,and the multi-objective optimization function is established.Then the optimization results of the control arm under single objective and multi-objective conditions are calculated.According to the optimization evolution trend of the optimization results,the control arm is remodeled and stiffeners are arranged to achieve the shape optimization of the control arm.Compared with the original design,the x-direction and Y-direction stiffness of the spherical hinge mounting point are increased by 4.7% and 41.8% respectively,and the ultimate yield strength of the X + /-direction and y + direction are increased by 23.8%,5.6% and 4.4% respectively.The performance of the control arm is improved by the shape optimization method,and it still meets the design requirements.